Yann Robert Chemla

Assistant Professor

Ph.D., Physics, University of California-Berkeley, 2001

Professor Yann Chemla received his PhD. in physics from the University of California, Berkeley in 2001. As an experimentalist in applied superconductivity, he developed an interest in biology through his study of magnetotactic bacteria with a superconducting magnetometer (Chemla et al., Biophys J., 1999), and the development of a biosensor based on functionalized magnetic nanoparticles (Chemla et al., PNAS, 2000). Prof. Chemla made the “leap” to biophysics as a postdoctoral fellow, moving down the hall to Prof. Carlos Bustamante’s laboratory at Berkeley. There, he learned the techniques of single-molecule manipulation and used an optical trap to study viral DNA packaging (Chemla et al., Cell, 2005). In 2005, he received one of the prestigious Career Awards at the Scientific Interface (CASI) from the Burroughs-Wellcome Fund. He joined the Department of Physics at Illinois in January 2007.

Other Activities

The cell is a factory of complex molecular structures that carry out specialized mechanical tasks and that behave remarkably like machines. Molecular motors, as they are called, are involved in such diverse processes as replicating the genome or transporting cargo across the cell, typically moving in discrete steps along a track — actin, microtubules, or DNA itself — converting chemical energy into mechanical work. A broad area of interest in my laboratory will be understanding the mechanism by which these molecular machines operate, and specifically, the process of mechano-chemical conversion.

Biophysical techniques that can detect such processes at the level of a single molecule are extremely powerful, since they are not subject to the averaging artifacts of traditional bulk biochemical methods. Optical traps, or “optical tweezers,” which utilize the force generated by focused laser light to manipulate microscopic objects, have been used extensively to measure the movements and forces exerted by individual molecular motors.

Recently, advances to this technique have made it possible to resolve motions on the scale of a single base pair of DNA, or only 3.4Å (see for example, Moffitt et al., PNAS, 2006). These high-resolution optical trapping techniques have the potential to reveal, for the first time, the stepwise motions of a host of molecular motors that translocate along or interact with nucleic acids and proteins. Access to this length scale should lead to a more detailed and refined understanding of many fundamental processes.

Students in my laboratory will work on all facets of research in this area: design and construction of instrumentation, development of biological systems for single-molecule manipulation, and quantitative analysis and modeling of collected data. Interested students and postdocs with backgrounds in physics, biology, chemistry, or related fields are welcome to contact me.

For more information:

http://research.physics.illinois.edu/chemlalab/

Honors and awards:

• Career Awards at the Scientific Interface (CASI), Burroughs-Wellcome Fund, 2005

Selected Publications:

• Min, T.L. Mears, P.J., Chubiz, L.M., Rao, C.V., Golding, I., Chemla, Y.R., (2009) “High-resolution, long-term characterization of bacterial motility using optical tweezers” Nature Methods. 6(11):831-835
• Landry, M.P., McCall, P.M., Qi, Z., Chemla, Y.R. (2009) “Characterization of photoactivated singlet oxygen damage in single-molecule optical trap experiments”, Biophys. J. 97(8), 2128-2136
• Aathavan, K., Politzer, A.T., Kaplan, A., Moffitt, J.R., Chemla, Y.R., Grimes, S., Jardine, P.J., Anderson, D.L., Bustamante, C. (2009) “Substrate Interactions and Promiscuity in a Viral DNA Packaging Motor” Nature, 461, 669-673.
• Ibarra, B., Chemla, Y.R., Plyasunov, S., Smith, S.B., Lázaro, J.M., Salas, M., Bustamante C. (2009) “Proofreading Dynamics of a Processive DNA Polymerase” EMBO J. 28, 2794–2802.
• Moffitt, J.R., Chemla, Y.R., Aathavan, K., Grimes, S., Jardine, P.J., Anderson, D.L., Bustamante, C. (2009) “Intersubunit coordination in a homomeric ring ATPase”, Nature, 457, 446-50.
• Moffitt, J.R., Chemla, Y.R., Smith, S.B., Bustamante, C. (2008) “Recent advances in optical tweezers” Ann. Rev. Biochem. 77, 19-1:19-24.
• Chemla, Y.R., Moffitt, J.R., Bustamante, C. (2008) “Exact solutions for kinetic models of macromo-lecular dynamics" J. Phys. Chem. B. 112, 6025-6044.
• Moffitt, J. R., Chemla, Y.R., Izhaky, D., Bustamante, C. (2006) “Differential detection of dual traps improves the spatial resolution of optical tweezers” Proc. Natl. Acad. Sci, 103, 9006-9011.
• Chemla, Y.R., Aathavan, K., Michaelis, J., Grimes, S., Jardine, P.J., Anderson, D.L., Bustamante, C. (2005) “Mechanism of force generation of a viral DNA packaging motor” Cell, 122, 683-692.